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Torque Reaction Rods


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1 hour ago, docc said:

Looking closely at the images in the article Mikko posted, seems that Daytona racer has a chassis rod on both sides?

1-C7-B1-D89-30-FE-4459-A3-DB-C5-AE3-FE15

Ones the brake torque rod docc. It was fashionable at one time on sport and race bikes then when front brakes became the major stopping force as the rear brake wasn't really used or needed much on a sports bike it faded out. Now MotoGP bikes are reaching the limit of front stopping power the rear has gone back to this to promote squat under braking and to get a little more braking ability from the rear. So racers are again hitting the rear brake a fraction of a second before the front and the torque rod is set up to create a little squat. This lowers the c of g a fraction at the rear and helps keep it down initially. Its all fractions though docc for the very elite racers and even for national level road racers it a minor distinction.

It was also thought that it isolated the rear brake forces from the swingarm and fed them into the chassis to help with wheel chatter on the brakes which was really more about decent suspension than brake forces.

Ciao

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The rear caliper on the Daytona race bike pictured is free to rotate on bearings on the axle same as the bevel box. Its just an inverted version of the bevel box and the torque is provided by the brak

Hmmmm , sounds like a new topic time .   My First Crash & Burn . 

Starting on page 53, bottom of the first column, they describe the Dr. John rear suspension...

11 minutes ago, Cabernet said:

And Docc, you're not gonna want your rear caliper moving around are you?

Right?

I see that the brake torque rod on the Daytona racer is likely tied to the swingarm (not the frame) just like the drum brake on my GB500. Seems that is solved on the V11 with the extended caliper bracket that is located by the pivot bolt through the swingarm (later V11 have a clip through the inboard tip of that bolt to prevent it backing out and sending us halfway to a bad day . . . :o

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5 hours ago, docc said:

Right?

I see that the brake torque rod on the Daytona racer is likely tied to the swingarm (not the frame) just like the drum brake on my GB500. Seems that is solved on the V11 with the extended caliper bracket that is located by the pivot bolt through the swingarm (later V11 have a clip through the inboard tip of that bolt to prevent it backing out and sending us halfway to a bad day . . . :o

The rear caliper on the Daytona race bike pictured is free to rotate on bearings on the axle same as the bevel box. Its just an inverted version of the bevel box and the torque is provided by the brake not the engine driven shaft.

This is a bike I built from the ground up in the early 1980's with my own designed and built anti dive which we thought was worth having at the time. I also built all the bodywork including the original plugs and moulds.

The dive mechanism is a leveraged version of a brake torque arm.

Chuck might like the red engine cases. I was very avant garde back then:)

Ciao

 

My old Motoplast Kawasaki circa 1986.Designed and build the ...

 

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Phil, you seem like a guy that's been building rockets for years and decided to play with paper airplanes here. 

I'm grateful.  Docc, Chuck and you and many others have provided much guidance.

That looks like a badass Kaw.   I think I am counting four bike header pipes.

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4 minutes ago, LowRyter said:

Phil, you seem like a guy that's been building rockets for years and decided to play with paper airplanes here. 

I'm grateful.  Docc, Chuck and you and many others have provided much guidance.

That looks like a badass Kaw.   I think I am counting four bike header pipes.

Yes rebuilt Kawasaki 900 powered with Malossi Carbs, Bitubo race shock and Magnesium racing Marzocchi adjustable forks.

Ciao

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OMG Phil,   That's an amazing display of work and skill, especially when it looks to me like it was a road bike, off the charts hard core.

     I had a '76 KZ900 back in the day and used to lust over the Rickman frame kit ad's in the cycle magazines, and dreamt of picking up a frame kit; thank god I was poor enough I never put that plan into action, because I realize now, the moment I would have opened the box, I would have been in over my head, lol.

     Very impressive!

     

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9 minutes ago, 80CX100 said:

OMG Phil,   That's an amazing display of work and skill, especially when it looks to me like it was a road bike, off the charts hard core.

     I had a '76 KZ900 back in the day and used to lust over the Rickman frame kit ad's in the cycle magazines, and dreamt of picking up a frame kit; thank god I was poor enough I never put that plan into action, because I realize now, the moment I would have opened the box, I would have been in over my head, lol.

     Very impressive!

     

A Rickman would have been a lot less work. A friend of mine has owned a Rickman Kawasaki since new and has recently completed a full resto on it. The Motoplast came in a kit that was frame, swing arm rear shock and bodywork inc fairing. That was it.The original glass work, all of it! was of such poor quality and fit I actually threw it in the dumpster as I knew I could design and make better myself. It was a lot of work and the set cowling is a fairly ordinary shape. The Rickman was far superior quality in every way and a much easier build. Italians, you get what you get.

Note the Nylon rear sprocket. Popular in the early 80's for about 2 minutes:) I had also mounted the battery under the swingarm which I may have been one of the first to do.

Ciao     

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12 minutes ago, Lucky Phil said:

A Rickman would have been a lot less work. A friend of mine has owned a Rickman Kawasaki since new and has recently completed a full resto on it. The Motoplast came in a kit that was frame, swing arm rear shock and bodywork inc fairing. That was it.The original glass work, all of it! was of such poor quality and fit I actually threw it in the dumpster as I knew I could design and make better myself. It was a lot of work and the set cowling is a fairly ordinary shape. The Rickman was far superior quality in every way and a much easier build. Italians, you get what you get.

Note the Nylon rear sprocket. Popular in the early 80's for about 2 minutes:) I had also mounted the battery under the swingarm which I may have been one of the first to do.

Ciao     

I noticed the funny color of the rear sprocket, wondered if it was aluminum, "Nylon", I don't imagine that would be a good idea.

i saw the square box under the swing arm and wondered if it would be a battery box.

All of these fancy race kits/frames/body work etc, I would have seen similar in magazines but that type of exotica was not something I would ever see in the flesh.

I find it all quite fascinating, definitely the stuff of dreams and legends.

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32 minutes ago, andy york said:

I would like to know more about the front brake set up and what was trying to be achieved.

Andy

It was a mechanical anti dive system to stop fork compression during braking. The torque from the caliper when the brake is applied is transmitted through the caliper mount which pivots on the axle and via the rods to a clamp on the fork leg under the lower triple clamp. Anti dive was a thing for a few years back in the 80's until it was understood that fork dive was actually a good thing. This is another case where the "theory" did't work in practice a bit like "telescopic forks dont work when the bike is leaned over" rubbish.

When you get fork dive under braking it shortens the trail which makes the steering quicker just when you need it to turn into the corner and it also transfers weight to the front tyre increasing the contact patch for extra grip. The dive also lowers the bikes C of G which helps keep the back wheel on the ground under heavy braking. By the time the GP guys found out anti dive sucked and they lost front braking power/grip and they couldn't keep the back wheel on the ground under heavy braking the manufactures had committed to it on their road models so it hung around on road bikes for maybe 4 or 5 years. I was behind the curve as usual in those days:)

Ciao  

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